package lingda.util;

import java.util.Arrays;
import java.util.List;

public class StringSimilarityUtil {

    private static int min(int one, int two, int three) {
        int min = one;
        if (two < min) {
            min = two;
        }
        if (three < min) {
            min = three;
        }
        return min;
    }

    public static int ld(String str1, String str2) {
        int d[][];    //矩阵  
        int n = str1.length();
        int m = str2.length();
        int i;    //遍历str1的  
        int j;    //遍历str2的  
        char ch1;    //str1的  
        char ch2;    //str2的  
        int temp;    //记录相同字符,在某个矩阵位置值的增量,不是0就是1  
        if (n == 0) {
            return m;
        }
        if (m == 0) {
            return n;
        }
        d = new int[n + 1][m + 1];
        for (i = 0; i <= n; i++) {    //初始化第一列
            d[i][0] = i;
        }
        for (j = 0; j <= m; j++) {    //初始化第一行
            d[0][j] = j;
        }
        for (i = 1; i <= n; i++) {    //遍历str1
            ch1 = str1.charAt(i - 1);
            //去匹配str2  
            for (j = 1; j <= m; j++) {
                ch2 = str2.charAt(j - 1);
                if (ch1 == ch2) {
                    temp = 0;
                } else {
                    temp = 1;
                }
                //左边+1,上边+1, 左上角+temp取最小  
                d[i][j] = min(d[i - 1][j] + 1, d[i][j - 1] + 1, d[i - 1][j - 1] + temp);
            }
        }
        return d[n][m];
    }

    public static double sim(String str1, String str2) {
        int ld = ld(str1, str2);
        return 1 - (double) ld / Math.max(str1.length(), str2.length());
    }

    public static void main(String[] args) {
        String searchString = "hero";
        List<String> strList = Arrays.asList("Heroes Season 3", "Show Me a Hero", "英雄第一季", "天堂口第一季", "Crematorio");
        strList.forEach(str -> System.out.println(str + " sim : " + sim(str.toLowerCase(), searchString.toLowerCase())));
    }
}